Following the sun

Being widely adopted on account of increased generation and improved internal rate of return (IRR), solar trackers are gaining prominence across the globe.

Times have changed for solar trackers. From being considered as an unnecessary luxury while setting up solar power plants to being regarded as an emerging viable tool to optimise grid, efficiency and utilisation, solar trackers are gaining ground.

It was not very long that developers were not too keen on investing on the additional costs despite the increase in plant performance with the use of trackers. Today, solar trackers are being adopted worldwide on account of increased generation and improved internal rate of return (IRR).

As the solar industry progresses, developers are increasingly becoming aware of the enhanced capacity utilisation factors (CUFs) that tracker implementation can bring about. However, being a nascent market, there is a lot of uncertainty in selecting the best trackers for a solar power plant, especially with regard to cost savings and generation output per mega watt they could bring about.

Solar trackers
Solar trackers come in conjunction with the mounting structures and help direct the panels in the direction the sun movement.

The benefits of solar trackers augment significantly when closer to the equatorial line and in a good DNI environment. Solar trackers provide steady and continuous power throughout the day enabling maximum solar radiation capture. This translates into clean, efficient and dependable power to run commercial, industrial and day-based activities without encountering the need for storage thus enabling a better, pollution free nation.

There are different kinds of solar trackers, such as single-axis and dual-axis trackers, and fixed-tilt trackers, all of which can be tailor fit for a unique site. Installation size, local weather, degree of latitude and electrical requirements are all important considerations that can influence the type of solar tracker best suited for a specific solar installation. Technology plays a crucial role in determining power generation and robust performance robust which is not seamless with older outdated technology.

Single-axis trackers mostly provide higher inverter efficiency due to lower overloading requirement, reduced cooling needs for inverters due to less need for over-sizing, increased direct current (DC) overloading capacity compared to seasonal and fixed tilt structures, reduced solar photovoltaic (PV) cell cracking issues, unlike seasonal tilt movement mechanisms, it also optimises grid efficiency, and operation and maintenance is also less since the need to clean panels is also pared. The horizontal, single-axis trackers are now the leading choice among traders since they can deliver 20-30 per cent more energy without the added costs and complexities of dual-axis trackers. Fixed-tilt trackers, however, can limit the efficiency of the system.

While the power generated by a 131/100-MW fixed-tilt system is anywhere around 217 millon kilo watt (kW) per year, the same amount of power is generated by a single-axis tracker with a size of 114/100 MW. The fixed-tilt system will have to be oversized to match the generation of a single-axis tracker.

Why trackers are gaining ground
The use of solar trackers can swell electricity production by around 40 per cent in some regions, compared with modules at a fixed angle. In any solar application, the conversion efficiency is improved when the modules are continually adjusted to the optimum angle as the sun traverses the sky. As improved efficiency means improved yield, use of trackers can make quite a difference to the income from a large plant. This is probably the reason for the emerging trend of mounting utility-scale solar installations on tracking systems.

It can bring about a CUF of 21 per cent. In comparison with solar plants without trackers, this means an increase in performance of around 20-25 per cent. Nowadays, most engineering procurement and construction (EPCs) guarantee a power production of 19 lakh units with trackers in comparison to 15-16 lakh units without them. During high wind conditions, the panels are aligned horizontally to reduce the load on the panels and the mounting structure thereby prolonging the life of the power plant.

Players in motion
NEXTracker and Array Technologies Inc (ATI) continue to stand as the leading suppliers of PV tracker systems across the world, with the former supplying most of the distribution systems and the latter providing maximum centralised systems. IHS Markit analysts say.

NEXTracker led the pack of players standing among top shipment rankers accounting for a third of all solar PV trackers sold worldwide in 2017. Array Technologies ranked second on the list while Soltec grabbed the third spot.The companies collectively shipped over 5 GW DC of PV tracker components globally in 2016, accounting for nearly 50 percent of the global tracker market during the year in terms of product shipments, reports say.

Further, NEXTracker has also announced delivery of 754-MW solar trackers to the Villanueva solar project. As the mounting solution provider on the project, NEXTracker, in turn, subcontracted with Swinerton Renewable Energy (SRE) to capitalise on Swinerton's experience with projects of this magnitude. While the company is providing batteries in markets like the US, it is providing tracking solutions to India currently and are introducing other technologies here due to the abundant growth prospects. Trackers are important solutions for India owing to the fact that customers here need energy not only in the middle of the day, but also early morning and late afternoon, according to NEXTracker.

Other players like Convert Italia, Arctech, Game Change Solar and Soltec performed in the market. However, players like Sun Action Trackers and First Solar had to taste the dust.

Growth of the global PV tracker market in 2016 swelled as more developers and [engineering, procurement and construction (EPC) contractors] continue to adopt tracking solutions for their utility-scale projects, in order to milk the improving levelised cost of energy (LCOE) of such systems, according to analysts.

Companies like Scorpius Trackers shared the analysis of one year's generation of 1.1 MW, with POWER TODAY. According to the analysis, the solar tracker
plant is equipped with Canadian solar panels, loading of 10 per cent on direct current, grid downtime of 8.8 per cent across the year, generation yield of
1.91 MU / MW, among others features.

The generation of 1.942 MW per megawatt energy was achieved in a year. The tracker ensures advantages over fixed tilt systems, especially where direct current loading brings in a lot of value addition in reducing AC+DC side BOS Costs. The voltage reduction due to horizontal position allows for accommodating more panels per string thus ensuring early wake-up and generation up to late evening. The ability to deliver consistent power as well as reduce the impact of backdowns with zero failure rate on tracking components resulted in just 8.9 per cent reduction in power delivered as against fixed tilt or seasonal for which impact would be much more severe, according to the company.

According to NEXTracker, the firm has 21 projects to be delivered to seven clients, including Adani, Cleanmax, ReNew Power and Suzlon, and is also receiving repeat orders currently.

Of market
The solar market is growing by leaps and bounds and trackers are contributing a significant portion to the market. The ability to deliver better quality at better economics tilts the scales in favour of good tracker technology with zero additional mechanical O&M ensuring maintenance costs lower than fixed/seasonal tilt solutions with none of the drawbacks.

Funding and mergers and acquisitions (M&A) in the solar sector amounted to around $1.6 billion in January-March, says research firm Mercom Capital Group. Japan's SoftBank, along with partners, have pledged $20-billion investment in solar power generation projects of India, despite the deal sizes being small.

With the government promising to set up a $350-million fund for funding the country's solar projects - an announcement made by Minister of State (Independent Charge) for Power and Renewable Energy, Raj Kumar Singh during the Future World Energy Summit (WFES) 2018 - hope glimmers that solar trackers will gain heavier footing in solar energy market. Singh had said that the International Solar Alliance (ISA) will help mobilise sufficient funds for these projects. Interim Director-General of ISA, Upendra Tripathy has mentioned about sealing as much as 100 projects by April 2018. During the event, lenders like YES Bank committed to financing solar projects of over $5 billion. CLP and NTPC also announced a partnership deal with the ISA and committed a voluntary contribution of $1 million each to the ISA fund corpus.

Further, some sizeable pension funds looking for long-term returns on green investments, are scouting for deals in the nation's solar sector, where Prime Minister Narendra Modi is targeting $100 billion in investment in the next five years.
Kotak Investment Banking expects at least 5 GW of solar power to be added from next year, most of it supported by overseas funds.

Solar power generation capacity in India has hit 12 GW in less than three years, on the back of lower module prices and borrowing costs, and government's thrust on clean energy. However, the same adds only 4 per cent to the total power capacity of about 315 GW.

By 2018, the Asia-Pacific region will be the largest regional market for trackers as Indian utility market grows and Chinese market matures. China, the world's biggest solar producer, more than doubled its capacity last year, to 77.42 GW. Considering that less than 70 per cent US GM projects are with trackers, USA will remain the leading market for trackers through 2021.

However, thanks to the debt-ridden power distribution companies (DISCOMS), factors like payment delays from discoms could impede investment plans. Experts also note that the bidding for projects in government auctions is too aggressive, with per unit prices slumping more than 70 per cent since 2010, that could give wet blanket to investor sentiment.

The pricing in India has been competitive being the lowest seen as the country is quickly pushing the scale through larger projects, with the sun being the top source of energy, according to NEXTracker.

Moreover, the ground mounting (GM) segment will contribute significantly to installations in future.

'GM segment accounts for 99 per cent of installation given the grid load requirements in the near future. However, new and improved designs will come together to deliver viable technology to rooftops when the demand is significant. The roof is the optimal place for trackers as space is limited with maximum generation requirements which is a pillar of tracking technology, ö Ritesh Pothan, Senior Vice President, Scorpius Trackers, told POWER TODAY.

Pros and cons
Over the past few years, the industry has started moving away from fixed-tilt racking structures to tracking due to high energy yield. Solar panel tracking solutions are a more advanced technology for mounting photovoltaic panels. Stationary mounts holding panels in a fixed position can limit productivity when in the wake of the sun passing to a less-than-optimal angle. The tracker is the following advantages.
Thanks to increased direct exposure to solar rays, trackers generate more electricity than their stationary counterparts which can be as much as 10 to 25 per cent depending on the geographic location of the tracking system.

Solar trackers generate more electricity in roughly the same amount of space needed for fixed-tilt systems, making them ideal for optimising land usage. In certain states, some utilities offer time of use (ToU) rate plans for solar power, which means the utility will purchase the power generated during the peak time of the day at a higher rate. In this case, it is beneficial to generate a greater amount of electricity during these peak times of the day.

Using a tracking system helps maximise the energy gains during these peak time periods. Advancements in technology and reliability in electronics and mechanics have reduced long-term maintenance concerns for tracking systems.

However, the downsides of using trackers include higher buying cost than their stationary counterparts due to the more complex technology and moving parts necessary for their operation. This is usually around a $0.08 û $0.10/W increase depending on the size and location of the project. The amount of maintenance required is also more than a traditional fixed rack, though the quality of the solar tracker can determine the amount and frequency of maintenance needed. Site preparation is also more in case of solar trackers including additional trenching for wiring and some additional grading.

Single-axis tracker projects also require an additional focus on company stability and bankability. When it comes to getting projects financed, these systems are more complex and thus are seen as a higher risk from a financier's viewpoint.

Solar trackers are generally designed for climates
with little to no snow making them a more viable solution in warmer climates. Fixed racking accommodates harsher environmental conditions more easily than tracking systems.

Fixed tracking systems offer more field adjustability than single-axis tracking systems. Fixed systems can generally accommodate up to 20 per cent slopes in the east-west direction while tracking systems typically offer less of a slope accommodation usually around 10 per cent in the north-south direction.

Besides, adding a solar tracking system usually entails addition of more equipment, moving parts and gears, that will require regular maintenance and repair or replacement of broken parts. Also, if the system breaks down on the back of panels being at an extreme angle, the loss of production until the system is functional again can be substantial. A solar tracker is also more prone to be damaged in a storm than the actual panels.

Warranties can be another sore point. A fixed-solar system that will last 30 years is usually accompanied by a 25-year power performance guarantee. But, a solar-tracked system comes only with a 5 to 10-year warranty.

Opportunities
With the economy's growth being on an upsurge and increasing number of people moving into the cities, power demand in Asia's third-largest economy is set to surge. According to the country's estimates, peak electricity demand will touch 690 GW (more than quadruple) in the next two decades, which would require rapid growth in generation and transmission capacity.

Trackers will be relevant for solar PV due to design optimisation leading to cost reduction. Trackers provide 100-150 bps increase in IRR despite the expected sharp decline in module prices, according to a report by Scorpius Trackers shared with POWER TODAY. The global value of tracker installations will top $4.9 billion (37.7 GW) in 2021, according to the report.

'The new way to follow the sun with these panels can produce 2-6 per cent more energy than a typical tracker. And that really helps the product economics', DanShugar, Chief Executive Officer, NEXTracker, told POWER TODAY.

Experts around the globe are of the view that India typically logs more than 300 days of sunshine a year, thereby enhancing the utility of solar power as against wind power in the country.

Growth for the PV tracker market is expected globally in the ensuing years, particularly in markets outside of the United States in Asia and Latin America as suppliers continue to convince developers and EPCs to utilise their solutions in light of the demonstrated benefits in terms of higher generation yields and broader power production over the course of the day versus fixed-tilt systems.

Moreover, while pricing could thwart the movement of growth markets, such issues are likely to be resolved, thanks to the large international suppliers and domestic market entrants.